St Paul's Apartments, Sheffield

The Tallest Building in Sheffield

Installation of 6,000sqm of Wicona unitised curtain walling has now been completed as part of the construction of a 32-storey tower – Sheffield’s tallest building. The £5m façade contract was delivered by Solaglas Contracting in partnership with Wicona.

The 101m tower is part of the City Lofts St Paul’s Apartments scheme – an ambitious £40m development and the focal point of the £180m Heart of the City regeneration project. Designed to be light and slender, the tower is highly glazed using nearly 700 Wicona unitised panels, which were prefabricated off site by Solaglas.

Maximising Work Off Site

The unitised pre-glazed panels were installed over a six-month period, at the rate of a floor per week – eliminating the need for scaffolding, improving site safety and cost efficiency, and allowing faster completion of the building envelope for earlier fitting out.

The completed tower is iconic in stature and has formed a commanding presence over the city skyline. Its construction used the latest off-site techniques, including pods for the kitchens, bathrooms and ensuites, prefabricated cylinder cupboards, and unitised curtain walling for the façade.

The Unitised Solution

The façade is glazed in clear low E glass to the vision areas, with enamel-coated black opaque glass used as vertical strips to conceal insulated walls, and champagne-coloured vertical spandrel panels with concave pressings to conceal structural columns and party walls. Aluminium-faced spandrel panels were used as horizontal bands between floors.

The curtain walling is capped to form a visible grid for a ‘picture frame’ appearance and the frames are finished in light brown. Bottom hung full-height vents were inserted into the unitised panels to naturally ventilate all the bedrooms, with a tilt/slide door for the living areas, and an internal glass balustrade which was fixed independently.

A Landmark Building

In addition to the extensive use of glazing, the tower has a variety of complementary external treatments, comprising specially-made terracotta rainscreen to the building ends, with bronze cladding to the rooftops, creating an elegant envelope for this landmark building. The tower provides 230 luxury apartments – a mix of one and two-bed apartments and penthouses, with a contemporary Conran design for city centre living. The two lower floors of the building provide commercial and retail space.

Comments from the Construction Team

Teresa Wesley, Associate Director, Conran & Partners:

“We worked closely with the Wicona team during the design phase. Our aim was to create a highly reflective façade for the tower, with contrasting clear and opaque areas of glass. The unitised approach allowed us to achieve the visual impact we had envisaged, and offers many site-related advantages. It provides much greater quality control, safety improvement benefits, and less material wastage. We would definitely specify this solution again.”

Jon Mangham, Project Manager, Shepherd Construction:

“The Wicona unitised solution removed the need for scaffolding or mast climbers on this project which was a really important safety benefit for the construction of such a high structure. The loadings on the scaffolding would have made it dangerous to work at such a height.”

“By completing the units off site in a manufacturing environment, we benefited from improved quality control and greater cost efficiency. This more systematic approach to façade construction reduced the risk of remedial works and gave us more programme certainty. It also allowed us to start fitting out at an earlier stage, as well as meet the most stringent performance and wind loading specifications.”

“This is a vastly superior alternative to conventional methods of façade construction, combining safety, quality control, efficiency and speed. I would definitely recommend it for similar projects.”

John Harvey, Business Manager, Solaglas:

“We set up a dedicated assembly facility for the project, with 43,000sqft of space allocated to the construction of the unitised panels. This purpose-built line and our close partnership with Wicona enabled tight control of the process, resulting in a high quality finish and service for the St Paul’s project.”

The Wicona approach to façade design gives specifiers, building contractors and developers the benefit of a seamless and fully co-ordinated service – from initial design concepts and specification, to fabrication, installation, testing and handover – with all the advantages of off-site construction for the building envelope.